Linux Blog

PASSMASS

NAME

passmass - change password on multiple machines

SYNOPSIS

passmass
[
host1 host2 host3 ...
]

INTRODUCTION

Passmass
changes a password on multiple machines. If you have accounts on
several machines that do not share password databases, Passmass can
help you keep them all in sync. This, in turn, will make it easier to
change them more frequently.

When Passmass runs, it asks you for the old and new passwords.
(If you are changing root passwords and have equivalencing, the old
password is not used and may be omitted.)

Passmass understands the "usual" conventions. Additional arguments
may be used for tuning. They affect all hosts which follow until
another argument overrides it. For example, if you are known as
"libes" on host1 and host2, but "don" on host3, you would say:

passmass host1 host2 -user don host3

Arguments are:

-user

User whose password will be changed. By default, the current user is used.

-rlogin

Use rlogin to access host. (default)

-slogin

Use slogin to access host.

-telnet

Use telnet to access host.

-program

Next argument is a program to run to set the password. Default is
"passwd". Other common choices are "yppasswd" and "set passwd" (e.g.,
VMS hosts). A program name such as "password fred" can be used to
create entries for new accounts (when run as root).

-prompt

Next argument is a prompt suffix pattern. This allows
the script to know when the shell is prompting. The default is
"# " for root and "% " for non-root accounts.

-timeout

Next argument is the number of seconds to wait for responses.
Default is 30 but some systems can be much slower logging in.

-su

Next argument is 1 or 0. If 1, you are additionally prompted for a
root password which is used to su after logging in. root's password
is changed rather than the user's. This is useful for hosts which
do not allow root to log in.

HOW TO USE

The best way to run Passmass is to put the command in a one-line shell
script or alias. Whenever you get a new account on a new machine, add
the appropriate arguments to the command. Then run it whenever you
want to change your passwords on all the hosts.

CAVEATS

Using the same password on multiple hosts carries risks. In
particular, if the password can be stolen, then all of your accounts
are at risk. Thus, you should not use Passmass in situations where
your password is visible, such as across a network which hackers are
known to eavesdrop.

On the other hand, if you have enough accounts with different
passwords, you may end up writing them down somewhere - and
that
can be a security problem. Funny story: my college roommate had an
11"x13" piece of paper on which he had listed accounts and passwords
all across the Internet. This was several years worth of careful work
and he carried it with him everywhere he went.
Well one day, he forgot to remove it from his jeans, and we found a
perfectly blank sheet of paper when we took out the wash the following
day!